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bflsw09
Sep 3, 2009, 06:57 PM
A thief is trying to escape from a parking garage after completing a robbery, and the thief's car is speeding toward the door of the parking garage (see figure). When the thief is L = 32 m from the door, a police officer flips a switch to close the garage door. The door starts at a height of 1.8 m and moves downward at 0.22 m/s. If the thief's car is 1.2 m tall, what should be the minimum speed of his car to escape?

ballengerb1
Sep 3, 2009, 07:07 PM
No figure to see

bflsw09
Sep 3, 2009, 07:14 PM
24189

Image is attached

Unknown008
Sep 6, 2009, 12:22 PM
For the car to escape in the limits, the height of the door have to be 1.2 m above the ground. Here, we'll assume that the car is 1.2m at a point only, and we'll consider the length of the car to be negligible.

Find the time for the door to be 1.2 m above the ground.
The car has to travel distance L within that time.
Can you find the speed?